CT scans-The appearance of CT scans, like radiographs, is based on the absorption and transmission of x rays, which depends on factors other than density. A better word is “attenuation,” which is “a collective term for the processes (absorption and scattering) by which the energy of an x-ray beam is diminished in its passage through matter” (2). Thus, on CT scans a “high-density lesion” is more appropriately referred to as a “high-attenuation lesion.” US scans-The term “lucency” was first used in reference to areas of the fluorescent screen that became brightly illuminated during fluoroscopy of structures of little opacity. Since US does not make use of light (except in the cathode ray tube), there has been general agreement (3) that such areas should be referred to as hypoechoic or anechoic. (“Lucent” should be avoided with reference to any modality other than fluoroscopy;
eg,
a “lucency”
on
a radiograph
area of decreased opacity.) MR images-Here, one sion, not its density.
refers
could
to the
be
referred
to as an
signal
intensity
(editor’s
page).
of a le-
References 1. 2.
Tuddenham Graphics Nomenclature terms ture
3.
WJ.
In defense 6:171-172.
1986;
Committee
for thoracic Committee
Md:
of the
Fleischner
radiology: recommendations of the Fleischner Society.
American Institute tee. Recommended thesda,
of opacity
of Ultrasound nomenclature:
American
Institute
Manilee Davis, Assistant Editorial RSNA Publications Department 2021 Spring Road, Suite 600 Oak Brook, IL 60521
Renal Arterial Rupture Transluminal Angioplasty U
Society. AJR
in Medicine physics and of Ultrasound
RadioGlossary
of
of the Nomencla1984; 143:509-517. Standards engineering.
CommitBe-
in Medicine,
1979.
Manager
References 1. Ashenburg
Complicating
From:
2.
Robert G. Levitt, MD, and Mark H. Wholey, MD Pittsburgh Vascular Institute, Shadyside Hospital 5230
Centre
Avenue,
Pittsburgh,
PA
mm Hg) without medication. Seven days later, the patient complained of low back pain. A right renal sonognam showed an aneurysm of the right renal artery at the angioplasty site. Soon thereafter the patient became unresponsive and pulseless and died. A postmortem examination revealed dissection of the renal artery intima and media and perforation of the adventitia, resulting in a large retnopenitoneal hematoma. In both our case and that of Ashenbung et al, selection of initial balloon diameter was based on measurement of the angiognaphic diameter of the renal artery beyond the stenosis. Ordinarily, a 10% magnification factor exists in conventional angiognaphic geometry, so that the renal artery is being slightly ovendilated with use of this technique (3,4). Renal antery rupture did not occur in either case as a result of this slight “oversizing” of the balloon, but rupture was produced when balloons 1 mm larger than the measurement of the renab artery were used. We are aware that Sos et al choose balboons 1 -2 mm larger than the measured diameter and have not encountered renal artery rupture in their patients (5) (Sos TA, personal communication, March 1990). However, use of an oversized balloon produced the only renal artery rupture in the series of 97 renal artery dilations reported by Ashenburg et al (1) and in Olin and Wholey’s series of oven 200 nenal artery dilations (2). We no longer use balloons larger than the measured angiographic diameter of the renal artery, even when the initial angioplasty leaves residual stenosis. We agree with Ashenbung et al that a national registry of interventional procedure complications, such as the one unden development by the Society of Cardiovascular and Interventional Radiology (SCVIR), is necessary to provide the data on which to base the selection of balloon size for renal artery angioplasty. Until such a registry becomes available, we do not recommend the use of balloons larger than the measured diameter of the renal artery for renal artery angioplasty, even when the initial angioplasty leaves residual stenosis.
3.
15232
tive Olin
management. JW, Wholey
Wholey dures
in
EJ, ed.
RJ, Rivera
FJ, Weigele
transluminal
JB.
angioplasty:
Radiology 1990; 174:983-985. MH. Rupture of the renal transluminal
MH,
Solomon
the
peripheral,
angioplasty. N.
Interventional
and
cardiology.
artery
JAMA
Angioplasty renal,
Renal
arterial
successful
and visceral
Philadelphia:
rup-
conservanine
1987;
days
after
257:518-520.
interventional circulation.
proceIn:
Saunders,
Topol
1990;
535-559.
In the March 1990 issue (RSNA-SCVIR special series) of Radiology, Ashenbung et al (1) reported rupture of a left renal anteny immediately following transluminal angioplasty of a stenosis
with
an
8-mm-diameter,
3-cm
176
#{149} Number
2
4.
Tegtmeyer
CJ,
plasty
of the
SM, eds. 1988;
Ultra-thin
balloon (Medi-tech/Boston Scientific, Watertown, Mass). In their case, the renal artery beyond the stenosis measured 6-7 mm at angiography, and the 8-mm balloon was used only aften dilations with 6- and 7-mm balloons left a residual stenosis of 50%-75%. This case has several features in common with those of a case of delayed renal artery rupture following transluminal angioplasty that we recently reported (2). Our case involved a 56-year-old woman with accelerated hypertension (blood pressure, 270/i40 mm Hg), who had previously undergone a left nephrectomy and who had an occlusion of the right renal artery near its origin. The right renal artery was reconstituted by collateral vessels from the middle adrenal artery and the lumbar arteries near the renal hilum. The angiographic measurement of the reconstituted renal antery was 6-7 mm. A 0.035-inch steerable wire was passed across the occlusion, followed by a 6-F catheter. A digital subtraction angiognam confirmed the necanalization of the renal artery with underlying stenosis at the site of the previous occlusion. An exchange wire was placed in position, followed by a 6-mm angioplasty balloon, which was inflated for 45 seconds at 6 atm. A 40% residual stenosis existed after angioplasty, and an 8-mm balloon was placed in position and inflated for 45 seconds at 6 atm. A digital subtraction angiognam showed no residual stenosis and no dissection of the renal antery. The patient’s blood pressure became controlled (i50/90
Volume
complicating
percutaneous
Editor:
nonostial
RJ, Blain
ture
5.
CD.
arteries.
Interventional
Percutaneous In:
transluminal
Castaneda-Zuniga
angioWR,
radiology.
Baltimore:
Williams
Techniques
of renal
angioplasty.
Tadavarthy
& Wilkins,
298-309.
Tegtmeyer gy
Kellum renal
1986;
Dr Ashenburg
CJ,
Sos
TA.
Radiolo-
161:577-586.
responds:
We appreciate the comments of Drs Levitt and Wholey concenning our recent case report (1) and their experience (2) of renal artery rupture following percutaneous transluminal angioplasty. We believe that our case was unique because of the history of long-term corticostenoid therapy and the role it may have played in rendering the arterial wall more susceptible to rupture. However, based on our recent experience, we agree that balloon size is best chosen by using the measurement obtamed directly from the arteriognam. We do not recommend oversizing by 1 or 2 mm, despite the excellent results reported by others who advocate this method (3). Although iO%-20% magnification is a commonly quoted figure in angiography, the actual magnification will vary as the object-film distance changes. In addition to individual anatomic variation, filming projection alters this relationship. Biplane filming technique may also overmagnify images, particularly if patient contact with the postenoantenior film changer is limited by the lateral film changer, as it is in some angiognaphic systems. Perhaps, if a difference of i-2 mm is crucial, we should all use an available internal reference facton, such as the angiognaphic catheter itself.
Radiology
#{149} 583
eg,
a “lucency”
on
a radiograph
area of decreased opacity.) MR images-Here, one sion, not its density.
refers
could
to the
be
referred
to as an
signal
intensity
(editor’s
page).
of a le-
References 1. 2.
Tuddenham Graphics Nomenclature terms ture
3.
WJ.
In defense 6:171-172.
1986;
Committee
for thoracic Committee
Md:
of the
Fleischner
radiology: recommendations of the Fleischner Society.
American Institute tee. Recommended thesda,
of opacity
of Ultrasound nomenclature:
American
Institute
Manilee Davis, Assistant Editorial RSNA Publications Department 2021 Spring Road, Suite 600 Oak Brook, IL 60521
Renal Arterial Rupture Transluminal Angioplasty U
Society. AJR
in Medicine physics and of Ultrasound
RadioGlossary
of
of the Nomencla1984; 143:509-517. Standards engineering.
CommitBe-
in Medicine,
1979.
Manager
References 1. Ashenburg
Complicating
From:
2.
Robert G. Levitt, MD, and Mark H. Wholey, MD Pittsburgh Vascular Institute, Shadyside Hospital 5230
Centre
Avenue,
Pittsburgh,
PA
mm Hg) without medication. Seven days later, the patient complained of low back pain. A right renal sonognam showed an aneurysm of the right renal artery at the angioplasty site. Soon thereafter the patient became unresponsive and pulseless and died. A postmortem examination revealed dissection of the renal artery intima and media and perforation of the adventitia, resulting in a large retnopenitoneal hematoma. In both our case and that of Ashenbung et al, selection of initial balloon diameter was based on measurement of the angiognaphic diameter of the renal artery beyond the stenosis. Ordinarily, a 10% magnification factor exists in conventional angiognaphic geometry, so that the renal artery is being slightly ovendilated with use of this technique (3,4). Renal antery rupture did not occur in either case as a result of this slight “oversizing” of the balloon, but rupture was produced when balloons 1 mm larger than the measurement of the renab artery were used. We are aware that Sos et al choose balboons 1 -2 mm larger than the measured diameter and have not encountered renal artery rupture in their patients (5) (Sos TA, personal communication, March 1990). However, use of an oversized balloon produced the only renal artery rupture in the series of 97 renal artery dilations reported by Ashenburg et al (1) and in Olin and Wholey’s series of oven 200 nenal artery dilations (2). We no longer use balloons larger than the measured angiographic diameter of the renal artery, even when the initial angioplasty leaves residual stenosis. We agree with Ashenbung et al that a national registry of interventional procedure complications, such as the one unden development by the Society of Cardiovascular and Interventional Radiology (SCVIR), is necessary to provide the data on which to base the selection of balloon size for renal artery angioplasty. Until such a registry becomes available, we do not recommend the use of balloons larger than the measured diameter of the renal artery for renal artery angioplasty, even when the initial angioplasty leaves residual stenosis.
3.
15232
tive Olin
management. JW, Wholey
Wholey dures
in
EJ, ed.
RJ, Rivera
FJ, Weigele
transluminal
JB.
angioplasty:
Radiology 1990; 174:983-985. MH. Rupture of the renal transluminal
MH,
Solomon
the
peripheral,
angioplasty. N.
Interventional
and
cardiology.
artery
JAMA
Angioplasty renal,
Renal
arterial
successful
and visceral
Philadelphia:
rup-
conservanine
1987;
days
after
257:518-520.
interventional circulation.
proceIn:
Saunders,
Topol
1990;
535-559.
In the March 1990 issue (RSNA-SCVIR special series) of Radiology, Ashenbung et al (1) reported rupture of a left renal anteny immediately following transluminal angioplasty of a stenosis
with
an
8-mm-diameter,
3-cm
176
#{149} Number
2
4.
Tegtmeyer
CJ,
plasty
of the
SM, eds. 1988;
Ultra-thin
balloon (Medi-tech/Boston Scientific, Watertown, Mass). In their case, the renal artery beyond the stenosis measured 6-7 mm at angiography, and the 8-mm balloon was used only aften dilations with 6- and 7-mm balloons left a residual stenosis of 50%-75%. This case has several features in common with those of a case of delayed renal artery rupture following transluminal angioplasty that we recently reported (2). Our case involved a 56-year-old woman with accelerated hypertension (blood pressure, 270/i40 mm Hg), who had previously undergone a left nephrectomy and who had an occlusion of the right renal artery near its origin. The right renal artery was reconstituted by collateral vessels from the middle adrenal artery and the lumbar arteries near the renal hilum. The angiographic measurement of the reconstituted renal antery was 6-7 mm. A 0.035-inch steerable wire was passed across the occlusion, followed by a 6-F catheter. A digital subtraction angiognam confirmed the necanalization of the renal artery with underlying stenosis at the site of the previous occlusion. An exchange wire was placed in position, followed by a 6-mm angioplasty balloon, which was inflated for 45 seconds at 6 atm. A 40% residual stenosis existed after angioplasty, and an 8-mm balloon was placed in position and inflated for 45 seconds at 6 atm. A digital subtraction angiognam showed no residual stenosis and no dissection of the renal antery. The patient’s blood pressure became controlled (i50/90
Volume
complicating
percutaneous
Editor:
nonostial
RJ, Blain
ture
5.
CD.
arteries.
Interventional
Percutaneous In:
transluminal
Castaneda-Zuniga
angioWR,
radiology.
Baltimore:
Williams
Techniques
of renal
angioplasty.
Tadavarthy
& Wilkins,
298-309.
Tegtmeyer gy
Kellum renal
1986;
Dr Ashenburg
CJ,
Sos
TA.
Radiolo-
161:577-586.
responds:
We appreciate the comments of Drs Levitt and Wholey concenning our recent case report (1) and their experience (2) of renal artery rupture following percutaneous transluminal angioplasty. We believe that our case was unique because of the history of long-term corticostenoid therapy and the role it may have played in rendering the arterial wall more susceptible to rupture. However, based on our recent experience, we agree that balloon size is best chosen by using the measurement obtamed directly from the arteriognam. We do not recommend oversizing by 1 or 2 mm, despite the excellent results reported by others who advocate this method (3). Although iO%-20% magnification is a commonly quoted figure in angiography, the actual magnification will vary as the object-film distance changes. In addition to individual anatomic variation, filming projection alters this relationship. Biplane filming technique may also overmagnify images, particularly if patient contact with the postenoantenior film changer is limited by the lateral film changer, as it is in some angiognaphic systems. Perhaps, if a difference of i-2 mm is crucial, we should all use an available internal reference facton, such as the angiognaphic catheter itself.
Radiology
#{149} 583
